A study on the relationship between Bacillus CalmetteGurin (BCG) vaccination and Covid-19 prevalence: Do other confounders warrant investigation?

The Covid-19 pandemic, which originated from Wuhan, Hubei province, China, and quickly spread to the rest of the globe is caused by SARS-CoV-2 coronavirus. Preliminary data suggest a relationship between the BCG vaccine and the prevalence of Covid-19. The vaccine is used in the prevention of tuberculosis, a disease that is most prevalent in developing countries. To determine the potential protective role of Bacillus Calmette-Guérin (BCG) vaccination, this study investigated the occurrence of Covid-19 and the relationship between the spread of Covid-19 in countries that offer BCG vaccination and those that do not. To determine if some SARS-CoV-2 strains were more prevalent than others, the study also performed a phylogenetic analysis of the strains from the representative countries. To achieve the objectives, the study utilized publicly available data on population size, vaccination coverage and Covid-19 cases. The study revealed a significant negative trend between countries that offer the BCG vaccine to the general population and the reported cases of Covid-19. The study proposes future molecular and immunological analyses to determine the potential role of BCG vaccination in protection against Covid-19. This will determine if BCG vaccine has antiviral properties, with the possibility of recommending it for widespread use if supported by scientific data. Key words: Bacillus Calmette-Guérin (BCG) vaccine, Covid-19, pandemic, phylogeographic analysis, vaccination.